فهرست مطالب

Archives of Razi Institute
Volume:62 Issue: 3, Summer 2007

  • تاریخ انتشار: 1386/08/11
  • تعداد عناوین: 8
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  • F. Ghazi, F. Sorooshi, M. Taghizadeh Pages 119-125
    Parechoviruses form one of the nine genera in the picornaviridae family, and include two human pathogens: Human parechovirus type1 and 2 (Hpev1 and Hpev2). The genome of picornaviruses encodes a single polyprotein, which undergoes a cleavage cascade performed by virus encoded proteases to give the final virus proteins. The primary cleavage occurs by 2A protein and this step is critical for viral life cycle. Recent sequence analysis suggests that Hpev1 is distinct from other picornaviruses and lacks the motifs believed to be involved in the protease function of 2A. The aim of this study was to analyze proteolytic activity of 2A protein in Hpev1. For this purpose we made several recombinant plasmids contain 2A region of parechovirus type1 genome and expressed in prokaryotic and in vitro systems under T7 promoter. Analyzing the expression products by SDS-PAGE revealed just a large single band (90 KDa), the same size as primary translation product. Whereas with plasmids include 3C gene several small bands were observed, indicating that processing had occurred. In
    Conclusion
    the results of this work show that Human parechovirus type1 has a processing strategy different from the other members of picornaviruses and in this virus, as in hepatovirus, 2A protein does not have a protease function.
  • M. Banani, M. Sehat, S.A. Pourbakhsh, B. Haerian, S. Shahsavandi Pages 127-133
    Egg drop syndrome (EDS) is caused by a hemagglutinating adenovirus which has become a major cause of lost egg production and sever economic losses in breeder and layer chicken flocks throughout the world. A PCR assay was optimized for detection of EDS virus in inoculated allantoic fluids (AFs) of duck and chicken emberyonated eggs. Two strains of EDS viruses were propagated in allantoic cavity of eggs. Then the virus DNA was extracted. PCR test was designed and carried out by specific primers. The 1900 bp band was detected in agar gel electrophoresis. Serial two fold dilutions of infected allantoic fluid were prepared. The HA test and PCR assay were carried out for each dilution and finally results were compared to each other. The PCR assay could detect some negative HA titers. This study clearly indicates the superiority of PCR assay over HA test for detection of EDS virus in AFs.
  • M. Aminian, E. Salehi, A. Khafri Pages 135-144
    Whooping cough (pertussis) is a highly contagious disease of the human respiratory tract, which is caused by Bordetella pertussis. Reemerge of pertussis in some highly immunized populations and divergency in gene order among several B. pertussis strains promoted this research to study the change of pertussis toxin (PT) and lipopolysacharide levels in response to the different environments. This study conducted an extensive investigation of antigenic modulation of B. pertussis strain 134 in the presence of different chemicals. One of the findings of this research, for the first time, was that barium ion has growth inhibitory role on B. pertussis 134, when added in high concentration to CBA plates. Nicotinic acid, magnesium sulfate, and magnesium chloride have shown the significant modulating effect on the basis of reduction of PT levels. Our data demonstrated quantitatively that the modulation of B. pertussis yields high levels of LPS. Our results have showed the strong modulatory effects of FeCl3 on reduction of PT levels. In general, this study provided collective data which are strongly applicable to explain modulation of B. pertussis, and also introduces new modulators which promote more study on gene order of B. pertussis.
  • G. Moazeni Jula, A. Jabbari Pages 145-149
    For evaluation the stability and potency of anthrax vaccine prepared in Razi Vaccine and Serum Research Institute in Iran, samples of different batches of vaccine were kept at 4-8 °C (refrigerator), 20-25 °C (room temperature) and 37 °C (incubator).The viable spores/ml of vaccines were determined using plate–counting method before and after holding at different temperatures monthly. Vaccine potency and duration of immunity conferred by the vaccine in animals were determined by challenging each group of vaccinated animals with virulent strain of Bacillus anthracis at 6 months intervals up to 24 months post vaccination. The results showed that the spores in vaccine remained viable at the recommended level for up to 3 years at 4 °C, 2 years at room temperature and 2 months at 37 °C. All the vaccinated animal groups resisted and survived against challenge 6, 12, 18 and 24 months post vaccination. So, it is concluded that the anthrax vaccine could be stable up to 3 years at 4-8 °C and the immunity conferred by vaccine in sheep and goats lasts for 24 months post vaccination.
  • F. Esna, Ashari, H. Mirchamsy, A. Shafyi, M. Taqavian, A. Mohammadi, M.P. Ashtiani, Gh.H. Sabiri, N. Sheikh, Mohammadi Pages 151-154
    Mass vaccination against viral infections such as mumps is a very noticeable and appropriate attempt in common health. Mumps infection has severe complications like deafness, infertility and meningitis. Attenuated live vaccine of mumps is produced and used to prevent the problems. Viral content in the monovalent vaccine is assayed with different methods. Nowadays international standards introduce microplate for titration of virus. In this study the different aspects were searched to assay vaccinal mumps strain, on microplate. Its results presented proper count of Vero cell and essential amount of viral inoculum to coculture, in certain concentration of CO2, on 96-well plate. Therefore with these ideal conditions, potency test of mumps virus was performed exactly, rapidly and economic with micromethod instead of cultivation in tube. Furthermore evaluation and reproducibility of the method accompanied with decreasing titer of < 0.5 log on microplate. The results showed the method is an efficient procedure for potency test in comparison with previous method.
  • R. Momayez, B. Khakpour, S.A. Pourbakhsh, M. Banani Pages 155-159
    Newcastle disease virus (NDV) is known as one of the most important endemic viral pathogen for various avian species such as ostrich, in Iran. Therefore, establishing a routine vaccination program against ND in ostrich flocks would be useful in order to reduce the danger of this infection. Newcastle disease occurs among the ostriches and leads to high rate of mortality while most of the losses are among the youngest ones. This experiment was designed to follow up the changes of maternal antibody in ostrich chicks during the first weeks of their life. At this point of view, 700 one day old ostrich chicks were monitored and every seven days interval 10 blood samples were taken regularly and the titers of maternal antibody in their sera were studied. The haemagglutination inhibition (HI) test was used to evaluate the amount of anti-ND antibody. After hatching this study followed up to 49th day. Due to our findings, the day 30 is recommended as a proper time to start the vaccination program against ND in flocks of ostrich chicks with maternal antibody.
  • A. Ezzi, S.A. Pourbakhsh, S. Moradi Bidhendi Pages 161-164
    I n a survey of pneumonia due to Mycoplasma 282 out of 12168 ovine and caprine lung condemnation were collected (2.32%). Mycoplasma spp. has been isolated from pneumonic cases in 4 sheep and 2 goats. PCR studies were confirmed the genus of Mycoplasma although attempting for identification of strains M. mycoides, M. capricolum/caprine pleuropneumonia and M. arginin were in failure. The lesions initially showed raised consolidation at the right cranio-ventral lobes. Histopathological observations revealed purulent interstitial pneumonia & bronchitis (33.33%) purulent bronchopneumonia (33.33%) purulent fibrinous pneumonia (16.6%) and progressive pneumonia (16.6%). This approach has the potential to allow the recognition of genus of Mycoplasma as a primary factor for inducing pneumonia.
  • M. Mossawi Shoshtary, R. Pilehchian Langroudi, L. Abdolmohammadi, A. Jabbari Pages 165-169
    Blackleg in cattle has been recognized since 1938 in Iran that mostly affects cattle in enzootic farm. Main object of this study was to prepare and formulate a concentrated potent vaccine for immunization of cattle against blackleg in Iran. Experimental concentrated blackleg vaccine was prepared according to the method described by FAO. The medium (Modified medium for production of experimental C. chauvoei vaccine by fermenter) consisting of peptone, glucose, sodium chloride, cysteine hydrochloride and yeast extract was prepared by fermenter and inoculated by Clostridium chauvoei strain for preparation of blackleg vaccine. Aluminum hydroxide gel adjuvant was added to the high yield vaccine. The vaccine was also concentrated by the method of precipitation. None of tested animals showed any local or general adverse reactions. All of vaccinated guinea pigs resisted the challenge with 4 MLD of virulent C. chauvoei.